/* Flyer: Learn!  Same notebook as Flyer: ruled paper, post-its, tape,
   ink blue and highlighter yellow. Light = paper, dark = chalkboard.
   Post-its keep dark ink in both themes, like a real sticky note. */
:root{
  --paper:#FBF7EC;--rule:#D7E5F3;--margin:#F2B3AD;--ink:#1F2A44;--soft:#4B5571;--accent:#2F5DA8;--accent-d:#24498A;
  --card:#FFFDF7;--line:rgba(31,42,68,.16);--edge:#1F2A44;--shade:#1F2A44;--hl:#FFE45C;--red:#C8413B;--good:#2E7D4F;--warn:#9A5410;
  --yellow:#FFEB85;--pink:#FFC8D5;--blue:#BFE3F8;--green:#CDEDB5;--orange:#FFD3A1;--lav:#DED0F6;
  --note-ink:#1F2A44;--note-soft:#4B5571;--soft-bg:#F3EEDD;
}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]){
  --paper:#1E2A25;--rule:rgba(255,255,255,.05);--margin:rgba(255,138,128,.22);--ink:#F4F1E6;--soft:#CFCBBD;--accent:#9CCBFF;--accent-d:#7FB4EE;
  --card:#26342E;--line:rgba(255,255,255,.16);--edge:#E9E5D6;--shade:rgba(0,0,0,.55);--hl:#F3E36A;--red:#FF8A80;--good:#8FD9A8;--warn:#F0B878;
  --yellow:#F1DE78;--pink:#EDB6C3;--blue:#A9D2EA;--green:#B8DCA1;--orange:#EDC08F;--lav:#CBBBEA;--soft-bg:#2C3B34;
}}
:root[data-theme="dark"]{
  --paper:#1E2A25;--rule:rgba(255,255,255,.05);--margin:rgba(255,138,128,.22);--ink:#F4F1E6;--soft:#CFCBBD;--accent:#9CCBFF;--accent-d:#7FB4EE;
  --card:#26342E;--line:rgba(255,255,255,.16);--edge:#E9E5D6;--shade:rgba(0,0,0,.55);--hl:#F3E36A;--red:#FF8A80;--good:#8FD9A8;--warn:#F0B878;
  --yellow:#F1DE78;--pink:#EDB6C3;--blue:#A9D2EA;--green:#B8DCA1;--orange:#EDC08F;--lav:#CBBBEA;--soft-bg:#2C3B34;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;font:17px/1.6 Nunito,system-ui,-apple-system,"Segoe UI",sans-serif;color:var(--ink);background:var(--paper);background-image:repeating-linear-gradient(transparent 0 31px,var(--rule) 31px 32px);min-height:100vh;overflow-x:hidden;position:relative}
body::before{content:"";position:absolute;left:max(14px,calc(50% - 640px));top:0;bottom:0;width:2px;background:var(--margin);pointer-events:none}
a{color:var(--accent)}
button,input,select,textarea{font:inherit;color:inherit}
:focus-visible{outline:3px solid var(--accent);outline-offset:2px;border-radius:6px}
.skip{position:absolute;left:-999px;top:8px;background:var(--card);padding:8px 12px;border-radius:8px;z-index:20}
.skip:focus{left:8px}
.sr{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
.wrap{max-width:1240px;margin:0 auto;padding:0 28px 0 44px;position:relative}
.marker{font-family:'Permanent Marker',cursive;font-weight:400;line-height:1.05;margin:0}
.hand{font-family:Caveat,cursive;font-size:24px;color:var(--soft);line-height:1.2;margin:0}
.small{font-size:14px;color:var(--soft)}
.hl{background:linear-gradient(transparent 55%,var(--hl) 55%)}
:root[data-theme="dark"] .hl{color:var(--ink);background:linear-gradient(transparent 62%,rgba(243,227,106,.35) 62%)}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]) .hl{background:linear-gradient(transparent 62%,rgba(243,227,106,.35) 62%)}}
sup,sub{font-size:.72em;line-height:0}
h1,h2,h3{margin:0}

/* header */
header.top{position:sticky;top:0;z-index:10;background:color-mix(in srgb,var(--paper) 93%,transparent);backdrop-filter:blur(6px);border-bottom:2px solid var(--line)}
header.top .wrap{display:flex;flex-wrap:wrap;align-items:center;gap:8px 22px;padding-top:12px;padding-bottom:12px}
.brand{display:flex;align-items:center;gap:8px;text-decoration:none;color:var(--ink);font-family:'Permanent Marker',cursive;font-size:25px;line-height:1}
.brand svg{width:26px;height:26px}
nav.main{display:flex;flex-wrap:wrap;gap:4px 18px;flex:1 1 auto}
nav.main a{color:var(--ink);text-decoration:none;font-weight:800;font-size:15px;padding:6px 0;border-bottom:3px solid transparent}
nav.main a[aria-current="page"]{border-bottom-color:var(--hl);font-weight:900}
.tools{display:flex;align-items:center;gap:10px}
.streak[hidden]{display:none}
.streak{display:inline-flex;align-items:center;gap:5px;background:var(--orange);color:var(--note-ink);text-decoration:none;font-weight:900;font-size:14px;padding:7px 12px;border-radius:4px 4px 12px 4px;transform:rotate(-2deg)}
.who{width:40px;height:40px;border-radius:50%;background:var(--card);color:var(--ink);display:flex;align-items:center;justify-content:center;font-weight:900;text-decoration:none;border:2px solid var(--edge)}
.who.in{background:#2F5DA8;color:#fff}
.search{display:flex;align-items:center;gap:8px;background:var(--card);border:2px solid var(--line);border-radius:999px;padding:7px 14px;min-width:0;flex:0 1 230px}
.search input{border:0;background:transparent;outline:none;width:100%;font-size:14px;min-width:0}

/* buttons */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;background:#2F5DA8;color:#fff;font-weight:900;padding:12px 20px;min-height:48px;border-radius:14px;border:2px solid #24498A;border-bottom-width:5px;text-decoration:none;font-size:16px;cursor:pointer;line-height:1.2}
.btn:hover{filter:brightness(1.06)}
.btn:active{border-bottom-width:2px;transform:translateY(3px)}
.btn.ghost{background:var(--card);color:var(--ink);border-color:var(--line)}
.btn.dark{background:#1F2A44;border-color:#11182A;color:#FFFDF7}
.btn.small{padding:8px 14px;min-height:40px;font-size:14px;border-radius:11px;border-bottom-width:4px}
.btn[disabled]{opacity:.5;cursor:default;filter:none}
.linkbtn{background:none;border:0;padding:0;color:var(--accent);font-weight:900;cursor:pointer;text-decoration:underline;font-size:15px}
.chip{display:inline-flex;align-items:center;gap:6px;background:var(--card);border:2px solid var(--line);border-radius:999px;padding:5px 13px;font-weight:800;font-size:14px}
.tag{display:inline-block;background:var(--hl);color:#1F2A44;border:2px solid #1F2A44;font-weight:900;font-size:12px;padding:2px 8px}

/* paper pieces */
.card{background:var(--card);border:2.5px solid var(--edge);border-radius:16px;box-shadow:6px 6px 0 var(--shade);padding:22px 24px}
.card.flat{box-shadow:none}
.note{position:relative;background:var(--yellow);color:var(--note-ink);padding:18px 20px;border-radius:3px 3px 18px 3px;box-shadow:0 5px 14px rgba(0,0,0,.14)}
.note a:not(.btn){color:#1F2A44}
.note .small:not(.btn){color:var(--note-soft)}
.note.pink{background:var(--pink)}.note.blue{background:var(--blue)}.note.green{background:var(--green)}.note.lav{background:var(--lav)}.note.orange{background:var(--orange)}
.note.tape::before{content:"";position:absolute;top:-9px;left:50%;margin-left:-26px;width:52px;height:16px;background:rgba(242,205,110,.9);transform:rotate(-3deg)}
.tilt-l{transform:rotate(-1deg)}.tilt-r{transform:rotate(1deg)}
.note h3,.note .t{font-family:'Permanent Marker',cursive;font-weight:400;font-size:21px;margin:0 0 6px;line-height:1.15}
.bar{height:10px;background:var(--card);border:2px solid var(--edge);border-radius:99px;overflow:hidden}
.bar>i{display:block;height:100%;background:#2F5DA8}
.note .bar{background:#FFFDF7;border-color:#1F2A44}

/* notebook covers */
.cover{position:relative;display:block;border-radius:4px 12px 12px 4px;border:2.5px solid #1F2A44;box-shadow:5px 5px 0 var(--shade);overflow:hidden;color:#1F2A44;text-decoration:none;background:var(--blue)}
.cover::before{content:"";position:absolute;left:0;top:0;bottom:0;width:18px;background:rgba(31,42,68,.16);border-right:2px solid #1F2A44}
.cover .label{position:absolute;left:32px;right:14px;top:18px;background:#FFFDF7;border:2px solid #1F2A44;border-radius:7px;padding:7px 10px 8px}
.cover .label small{display:block;font-family:Caveat,cursive;font-size:16px;color:#4B5571;line-height:1}
.cover .label b{display:block;font-weight:900;font-size:17px;line-height:1.15;margin-top:2px}
.cover .glyph{position:absolute;left:32px;right:14px;top:112px;text-align:center;font-family:'Permanent Marker',cursive;font-size:44px;line-height:1.05}
.cover .meta{position:absolute;left:32px;right:14px;bottom:12px;font-weight:800;font-size:13px}
.cover .tag{position:absolute;right:-4px;top:90px;transform:rotate(6deg)}
.cover.yellow{background:var(--yellow)}.cover.pink{background:var(--pink)}.cover.blue{background:var(--blue)}.cover.green{background:var(--green)}.cover.orange{background:var(--orange)}.cover.lav{background:var(--lav)}
a.cover{transition:transform .15s}
a.cover:hover{transform:translateY(-4px) rotate(-1deg)}

/* browse */
.hero{display:flex;flex-wrap:wrap;align-items:center;gap:40px;padding-top:48px;padding-bottom:24px}
.hero .copy{flex:1 1 480px;min-width:0}
.hero h1{font-size:clamp(42px,6.4vw,74px);margin:4px 0 16px}
.hero .lede{font-size:clamp(18px,2vw,21px);max-width:36ch;margin:0 0 24px}
.hero .cta{display:flex;flex-wrap:wrap;gap:12px}
.hero .stage{flex:1 1 380px;min-width:0;position:relative;display:flex;justify-content:center;padding:18px 0 34px}
.hero .stage .cover{width:280px;height:366px;transform:rotate(-3deg);box-shadow:9px 9px 0 var(--shade)}
.hero .stage .cover::before{width:26px}
.hero .stage .cover .label{left:44px;right:20px;top:28px;padding:10px 14px}
.hero .stage .cover .label b{font-size:25px}
.hero .stage .cover svg{position:absolute;left:56px;top:140px}
.hero .stage .cover .meta{left:44px;right:20px;bottom:20px;font-size:14px}
.hero .upnext{position:absolute;right:0;top:0;width:214px;transform:rotate(4deg)}
.hero .peter{position:absolute;left:2%;bottom:-4px}
.banner{display:flex;flex-wrap:wrap;gap:6px 16px;align-items:center;margin:10px 0 8px}
.banner b{font-family:'Permanent Marker',cursive;font-weight:400;font-size:20px}
.rowhead{display:flex;flex-wrap:wrap;align-items:baseline;gap:4px 14px;margin-top:34px}
.rowhead h2{font-size:30px}
.rail{display:flex;gap:26px;overflow-x:auto;padding:18px 28px 28px 4px;margin-right:-28px;scrollbar-width:thin}
.rail .cover{flex:0 0 200px;height:258px}
.cont{flex:0 0 340px;display:flex;gap:14px;text-decoration:none;color:var(--ink);background:var(--card);border:2.5px solid var(--edge);border-radius:14px;box-shadow:5px 5px 0 var(--shade);padding:13px}
.cont .mini{flex:0 0 78px;height:102px;border-radius:3px 9px 9px 3px;border:2px solid #1F2A44;display:flex;align-items:center;justify-content:center;font-family:'Permanent Marker',cursive;font-size:20px;color:#1F2A44;text-align:center;line-height:1.05;padding:4px}
.cont .info{flex:1;min-width:0;display:flex;flex-direction:column;gap:3px}
.cont .info b{font-weight:900;font-size:18px;line-height:1.2}
.cont .info span{font-size:14px;color:var(--soft)}
.cont .prog{margin-top:auto;display:flex;align-items:center;gap:8px;font-weight:900;font-size:13px}
.cont .prog .bar{flex:1}
.feats{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:24px;margin-top:20px}
.feats a{text-decoration:none}
.plans{display:flex;flex-wrap:wrap;gap:16px 40px;margin-top:34px;border:2.5px dashed var(--line);border-radius:16px;padding:22px 24px;background:var(--card)}
.plans>div{flex:1 1 340px}
.results{display:flex;flex-direction:column;gap:10px;margin:18px 0}
.results a{display:flex;gap:12px;align-items:center;background:var(--card);border:2px solid var(--line);border-radius:12px;padding:10px 14px;text-decoration:none;color:var(--ink);font-weight:800}
.results a span{color:var(--soft);font-weight:700;font-size:14px}
footer.site{margin-top:56px;border-top:2px solid var(--line);padding:24px 0 44px;font-size:14px;color:var(--soft)}
footer.site .wrap{display:flex;flex-wrap:wrap;gap:6px 24px}
footer.site a{color:var(--soft)}

/* course page */
.crumbs{font-size:15px;font-weight:800;color:var(--soft);padding-top:22px}
.crumbs a{color:var(--soft)}
.chead{display:flex;flex-wrap:wrap;gap:40px;padding-top:26px;align-items:flex-start}
.chead .cover{flex:0 0 240px;height:316px;transform:rotate(-2deg);box-shadow:8px 8px 0 var(--shade)}
.chead .cover .label b{font-size:21px}
.chead .cover .glyph{top:140px;font-size:54px}
.chead .info{flex:1 1 480px;min-width:0}
.chead h1{font-size:clamp(40px,5.4vw,62px);margin:2px 0 12px}
.chips{display:flex;flex-wrap:wrap;gap:9px;margin:0 0 20px}
.cols{display:flex;flex-wrap:wrap;gap:36px;align-items:flex-start;padding-top:34px}
.cols>.mainc{flex:999 1 560px;min-width:0}
.cols>aside{flex:1 1 300px;max-width:400px;min-width:0;display:flex;flex-direction:column;gap:24px}
.units{background:var(--card);border:2.5px solid var(--edge);border-radius:16px;box-shadow:6px 6px 0 var(--shade);overflow:hidden}
.unit+.unit{border-top:1.5px solid var(--line)}
.unit>button{width:100%;display:flex;align-items:center;gap:14px;padding:14px 18px;background:transparent;border:0;text-align:left;cursor:pointer;min-height:58px}
.unit>button[aria-expanded="true"]{background:color-mix(in srgb,var(--hl) 16%,transparent)}
.unit .num{flex:0 0 38px;height:38px;border-radius:50%;border:2.5px solid var(--edge);display:flex;align-items:center;justify-content:center;font-weight:900;font-size:15px;background:var(--card)}
.unit .num.done{background:var(--green);color:#1F2A44}.unit .num.now{background:var(--hl);color:#1F2A44}
.unit .ut{flex:1;min-width:0}
.unit .ut b{display:block;font-weight:900;font-size:18px;line-height:1.25}
.unit .ut span{display:block;font-size:14px;color:var(--soft)}
.unit .st{font-weight:900;font-size:13px;color:var(--soft);white-space:nowrap}
.unit .st.done{color:var(--good)}.unit .st.now{color:var(--accent)}
.unit .body{padding:2px 18px 16px 70px;display:flex;flex-direction:column;gap:8px}
.lrow{display:flex;align-items:center;gap:12px;text-decoration:none;color:var(--ink);padding:10px 13px;border-radius:10px;background:var(--soft-bg);border:2px solid transparent;font-weight:800;font-size:15px}
.lrow:hover{border-color:var(--edge)}
.lrow .box{flex:0 0 22px;height:22px;border-radius:6px;border:2px solid var(--edge);display:flex;align-items:center;justify-content:center;font-weight:900;font-size:13px;background:var(--card)}
.lrow .box.done{background:var(--green);color:#1F2A44}
.lrow .t{flex:1}.lrow .len{font-size:13px;color:var(--soft);font-weight:700}
.soon{font-size:14px;color:var(--soft);padding:6px 2px}
.weak .w{margin-bottom:11px}
.weak .w .l{display:flex;justify-content:space-between;gap:10px;font-weight:800;font-size:14px}
.weak .w .l span:first-child i{font-style:normal;font-weight:700;color:var(--soft)}
.weak .bar{height:8px;border-width:1.5px;margin-top:4px}
.weak .lo .bar i{background:var(--red)}.weak .lo .p{color:var(--red)}
.weak .mid .bar i{background:#E8A15C}.weak .mid .p{color:var(--warn)}

/* lesson */
.lesson{display:grid;grid-template-columns:200px minmax(0,1fr) 330px;gap:30px;padding-top:26px;align-items:start}
.lesson .toc{position:sticky;top:84px;display:flex;flex-direction:column;gap:6px}
.lesson .toc a{display:flex;gap:9px;align-items:center;text-decoration:none;color:var(--ink);font-weight:800;font-size:15px;padding:8px 11px;border-radius:10px}
.lesson .toc a:hover{background:var(--soft-bg)}
.lesson .content{display:flex;flex-direction:column;gap:24px;min-width:0}
.lesson h1{font-size:clamp(36px,4.6vw,52px);margin:0 0 14px}
.lesson h2{font-family:'Permanent Marker',cursive;font-weight:400;font-size:26px;margin:0 0 8px}
.prose p{margin:0 0 12px;font-size:17.5px;line-height:1.65}
.prose h3{font-size:19px;font-weight:900;margin:18px 0 6px}
.prose ul,.prose ol{margin:0 0 12px;padding-left:22px}
.prose li{margin-bottom:5px}
.mathline{font-size:21px;font-weight:800;text-align:center;margin:12px 0 14px;padding:10px;background:var(--soft-bg);border-radius:10px;overflow-x:auto}
.tip{background:var(--green);color:var(--note-ink);border-radius:3px 3px 14px 3px;padding:12px 16px;margin:0 0 12px;font-size:16px}
.tip b{font-family:'Permanent Marker',cursive;font-weight:400;margin-right:6px}
.tablewrap{overflow-x:auto;margin:0 0 12px}
table.t{border-collapse:collapse;width:100%;font-size:15.5px;background:var(--card)}
table.t th,table.t td{border:1.5px solid var(--line);padding:8px 10px;text-align:left;vertical-align:top}
table.t th{background:var(--soft-bg);font-weight:900}
.steps{margin:0;padding-left:24px;font-size:16.5px;line-height:1.8}
.turn .q{font-size:21px;font-weight:900;line-height:1.4;margin:0 0 14px}
.turn .ansrow{display:flex;flex-wrap:wrap;gap:10px;align-items:flex-end;margin-bottom:10px}
.turn label{display:flex;flex-direction:column;gap:4px;font-weight:800;font-size:14px}
.in{padding:10px 14px;border:2.5px solid #1F2A44;border-radius:10px;background:#FFFDF7;color:#1F2A44;font-size:18px;width:190px;max-width:100%}
.choices{display:flex;flex-direction:column;gap:9px;margin-bottom:12px}
.choice{display:flex;align-items:center;gap:12px;width:100%;text-align:left;font-weight:800;font-size:16.5px;padding:11px 14px;min-height:50px;border-radius:12px;border:2.5px solid rgba(31,42,68,.25);background:#FFFDF7;color:#1F2A44;cursor:pointer}
.choice .let{flex:0 0 30px;height:30px;border-radius:50%;border:2.5px solid #1F2A44;display:flex;align-items:center;justify-content:center;font-weight:900;background:#FFFDF7;font-size:14px}
.choice[aria-pressed="true"]{border-color:#1F2A44;background:#FFF6C9}
.choice[aria-pressed="true"] .let{background:#FFE45C}
.choice.right{border-color:#2E7D4F;background:#E7F6DC}.choice.wrong{border-color:#C8413B;background:#FFE9EC}
.fb{font-weight:900;font-size:16px;margin:0 0 8px}
.fb.ok{color:#2E7D4F}.fb.no{color:#C8413B}
.card .fb.ok{color:var(--good)}.card .fb.no{color:var(--red)}
.lnav{display:flex;justify-content:space-between;flex-wrap:wrap;gap:12px;align-items:center}
.peterbox{position:sticky;top:84px;display:flex;flex-direction:column;gap:12px;padding:16px}
.peterbox .head{display:flex;align-items:center;gap:10px}
.peterbox .head b{font-family:'Permanent Marker',cursive;font-weight:400;font-size:21px;line-height:1;display:block}
.chat{display:flex;flex-direction:column;gap:10px;max-height:380px;overflow-y:auto}
.msg{max-width:92%;padding:10px 13px;font-size:15px;line-height:1.5;border-radius:14px;white-space:pre-wrap;overflow-wrap:anywhere}
.msg.me{align-self:flex-end;background:var(--lav);color:var(--note-ink);border-radius:14px 14px 4px 14px}
.msg.pe{align-self:flex-start;background:var(--soft-bg);border:2px solid var(--line);border-radius:14px 14px 14px 4px}
.modes{display:flex;flex-wrap:wrap;gap:7px}
.modes button{font-weight:800;font-size:13px;padding:7px 11px;min-height:38px;border-radius:999px;border:2px solid var(--edge);background:var(--card);cursor:pointer}
.ask{display:flex;gap:8px}
.ask input{flex:1;min-width:0;padding:10px 12px;border:2px solid var(--line);border-radius:10px;background:var(--card);font-size:15px}
.ask button{flex:0 0 46px;height:46px;border-radius:10px;border:2px solid #24498A;background:#2F5DA8;display:flex;align-items:center;justify-content:center;cursor:pointer}

/* graph + timeline widgets */
.graphbox{display:flex;flex-wrap:wrap;gap:22px;align-items:center}
.graphbox svg{flex:0 1 500px;max-width:100%;height:auto;background:var(--soft-bg);border:2px solid var(--line);border-radius:10px}
.graphbox .ctl{flex:1 1 200px;display:flex;flex-direction:column;gap:14px}
.graphbox label{display:flex;flex-direction:column;gap:4px;font-weight:900;font-size:15px}
input[type=range]{accent-color:#2F5DA8;width:100%}
.eq{font-size:21px;font-weight:900}
.tl{position:relative;overflow-x:auto;padding:14px 4px 22px;scrollbar-width:thin}
.tl .track{position:relative;display:flex;gap:16px;width:max-content}
.tl .track::before{content:"";position:absolute;left:0;right:0;top:76px;height:4px;background:var(--edge);border-radius:2px}
.tl button{position:relative;flex:0 0 146px;display:flex;flex-direction:column;align-items:center;gap:9px;background:transparent;border:0;cursor:pointer;padding:0}
.tl .yr{font-family:'Permanent Marker',cursive;font-size:26px;height:50px;display:flex;align-items:flex-end}
.tl .yr.long{font-size:20px}
.tl .dot{width:24px;height:24px;border-radius:50%;border:3px solid var(--edge);background:var(--card);position:relative;z-index:1}
.tl .ev{width:138px;min-height:70px;border:2.5px solid rgba(31,42,68,.3);border-radius:4px 4px 14px 4px;padding:7px 9px;font-weight:900;font-size:13.5px;line-height:1.3;color:#1F2A44;text-align:left}
.tl button[aria-pressed="true"] .dot{background:var(--hl)}
.tl button[aria-pressed="true"] .ev{border-color:#1F2A44;box-shadow:4px 4px 0 var(--shade)}
.eras{display:flex;flex-wrap:wrap;gap:6px 16px;font-size:13px;font-weight:800;margin-bottom:4px}
.eras span{display:flex;align-items:center;gap:6px}
.eras i{width:15px;height:15px;border-radius:4px;border:1.5px solid var(--edge)}
.tldetail .yr{font-family:'Permanent Marker',cursive;font-size:36px;margin-right:12px}

/* review */
.fc{position:relative;width:100%;min-height:310px;background:var(--card);border:3px solid var(--edge);border-radius:18px;box-shadow:8px 8px 0 var(--shade);padding:44px 36px;cursor:pointer;display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center}
.fc.back{background:color-mix(in srgb,var(--hl) 22%,var(--card))}
.fc .side{position:absolute;top:14px;left:20px;font-family:Caveat,cursive;font-size:22px;color:var(--soft)}
.fc .txt{font-size:clamp(21px,3vw,30px);font-weight:900;line-height:1.35;max-width:32ch}
.fc.back .txt{font-size:clamp(18px,2.4vw,23px);font-weight:800}
.fc .hint{position:absolute;bottom:14px;font-size:13px;font-weight:800;color:var(--soft)}
.rate{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px}
.rate button{min-height:64px;border-radius:14px;border:2.5px solid #1F2A44;border-bottom-width:5px;color:#1F2A44;cursor:pointer}
.rate button b{display:block;font-weight:900;font-size:17px}.rate button span{display:block;font-size:13px}
.rate .a{background:var(--pink)}.rate .h{background:var(--yellow)}.rate .g{background:var(--green)}
.week{display:grid;grid-template-columns:repeat(7,minmax(0,1fr));gap:6px;margin:12px 0}
.week div{display:flex;flex-direction:column;align-items:center;gap:4px;font-size:12px;font-weight:800}
.week i{width:30px;height:30px;border-radius:50%;border:2px solid #1F2A44;background:#FFFDF7;display:flex;align-items:center;justify-content:center;font-style:normal;font-weight:900;font-size:13px}
.week i.on{background:#FFE45C}
.week i.today{box-shadow:0 0 0 3px rgba(31,42,68,.25)}
.empty{text-align:center;padding:40px 20px}

/* exam */
.exambar{background:#1F2A44;color:#FBF7EC;position:sticky;top:0;z-index:12}
.exambar .wrap{display:flex;flex-wrap:wrap;align-items:center;gap:10px 22px;padding-top:12px;padding-bottom:12px}
.exambar b{font-family:'Permanent Marker',cursive;font-weight:400;font-size:21px}
.exambar .name{flex:1 1 220px;font-weight:800;font-size:15px;opacity:.88}
.timer{display:flex;align-items:center;gap:7px;background:#FFE45C;color:#1F2A44;font-weight:900;font-size:17px;padding:7px 13px;border-radius:10px}
.timer.low{background:#FFC8D5}
.exambar .btn{background:transparent;border:2px solid rgba(251,247,236,.55);color:#FBF7EC;min-height:40px;padding:7px 14px;font-size:15px}
.qmap{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:7px}
.qmap button{height:40px;border-radius:8px;border:2px solid var(--line);background:var(--card);font-weight:900;font-size:14px;cursor:pointer}
.qmap .ans{background:var(--green);color:#1F2A44}.qmap .flag{background:var(--pink);color:#1F2A44}.qmap .now{background:var(--hl);color:#1F2A44;border-color:var(--edge)}
.legend{display:flex;flex-wrap:wrap;gap:6px 14px;margin-top:12px;font-size:13px;font-weight:800}
.legend span{display:flex;align-items:center;gap:6px}.legend i{width:14px;height:14px;border-radius:4px;border:1.5px solid var(--edge)}
.score{font-family:'Permanent Marker',cursive;font-size:64px;line-height:1}
.rev{border-top:1.5px solid var(--line);padding:16px 0}
.rev .q{font-weight:900;font-size:17px;margin:0 0 6px}
.rev .a{font-size:15.5px;margin:0 0 4px}
.rev .mark{font-weight:900}.rev .mark.ok{color:var(--good)}.rev .mark.no{color:var(--red)}

/* scan */
.drop{display:flex;flex-direction:column;align-items:center;gap:8px;text-align:center;padding:30px 20px;border:3px dashed var(--line);border-radius:18px;background:var(--card);cursor:pointer}
.drop.over{border-color:var(--accent)}
.tabs{display:inline-flex;background:var(--card);border:2.5px solid var(--edge);border-radius:999px;padding:4px}
.tabs button{font-weight:900;font-size:15px;padding:9px 17px;min-height:44px;border-radius:999px;border:0;background:transparent;cursor:pointer}
.tabs button[aria-selected="true"]{background:var(--hl);color:#1F2A44}
.photo{position:relative;max-width:640px;margin:0 auto;transform:rotate(-1deg);box-shadow:0 14px 30px rgba(0,0,0,.25);border-radius:4px;line-height:0}
.photo img{width:100%;height:auto;display:block;border-radius:4px}
.photo .band{position:absolute;left:2%;right:2%;border-radius:8px;pointer-events:none}
.photo .band.key{background:rgba(255,228,92,.4)}
.photo .band.check{border:3px solid #C8413B;border-radius:40px}
.photo .band.answer{background:rgba(120,190,235,.3)}
.photo .pin{position:absolute;left:-13px;width:28px;height:28px;margin-top:-14px;border-radius:50%;border:2.5px solid #1F2A44;background:#FFFDF7;color:#1F2A44;font-weight:900;font-size:13px;display:flex;align-items:center;justify-content:center;line-height:1}
.pnotes{display:flex;flex-direction:column;gap:10px;margin-top:26px}
.pnotes li{display:flex;gap:10px;align-items:flex-start;font-size:15.5px}
.pnotes ol{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:10px}
.pnotes .n{flex:0 0 28px;height:28px;border-radius:50%;border:2.5px solid var(--edge);display:flex;align-items:center;justify-content:center;font-weight:900;font-size:13px}
.pnotes .k{font-weight:900}
.pnotes .k.check{color:var(--red)}.pnotes .k.key{color:var(--warn)}.pnotes .k.answer{color:var(--accent)}
textarea.fix{width:100%;min-height:260px;padding:14px 16px;border:2.5px solid var(--edge);border-radius:12px;background:var(--card);font-size:16px;line-height:1.6}
.meter{display:flex;gap:6px;margin:8px 0}
.meter i{flex:1;height:10px;border-radius:99px;background:var(--line)}
.meter i.on{background:#2F5DA8}
.spin{width:44px;height:44px;border-radius:50%;border:5px solid var(--line);border-top-color:var(--accent);animation:sp 1s linear infinite;margin:0 auto}
@keyframes sp{to{transform:rotate(360deg)}}
.form{display:flex;flex-direction:column;gap:14px;max-width:420px}
.form label{display:flex;flex-direction:column;gap:5px;font-weight:800;font-size:15px}
.form input{padding:11px 14px;border:2.5px solid var(--edge);border-radius:10px;background:var(--card);font-size:17px}
#toast{position:fixed;left:50%;bottom:22px;transform:translateX(-50%) translateY(20px);background:#1F2A44;color:#FFFDF7;font-weight:800;font-size:15px;padding:11px 18px;border-radius:12px;opacity:0;pointer-events:none;transition:.25s;z-index:30;max-width:90vw;text-align:center}
#toast.on{opacity:1;transform:translateX(-50%)}

@media (max-width:1080px){
  .lesson{grid-template-columns:minmax(0,1fr)}
  .lesson .toc{display:none}
  .peterbox{position:static}
}
@media (max-width:640px){
  body{font-size:16px}
  .wrap{padding:0 16px 0 26px}
  body::before{left:12px}
  header.top{position:static}
  header.top .wrap{gap:6px 12px;padding-top:10px;padding-bottom:8px}
  nav.main{order:3;flex-basis:100%;gap:2px 14px}
  nav.main a{font-size:14px}
  .brand{font-size:22px}
  .lesson .toc,.peterbox{top:12px}
  .search{flex:1 1 120px}
  .hero{padding-top:28px;gap:26px}
  .hero .upnext{position:static;transform:rotate(1deg);width:auto;margin-top:22px}
  .hero .stage{flex-direction:column;align-items:center;padding-bottom:6px}
  .hero .peter{left:-6px;bottom:auto;top:250px}
  .rail{gap:18px;margin-right:-16px;padding-right:16px}
  .rail .cover{flex-basis:168px;height:226px}
  .rail .cover .glyph{top:104px;font-size:36px}
  .cont{flex-basis:290px}
  .chead{gap:24px}
  .chead .cover{flex-basis:170px;height:224px}
  .chead .cover .glyph{top:104px;font-size:38px}
  .unit .body{padding-left:18px}
  .unit .st{display:none}
  .card{padding:18px 16px}
  .fc{padding:44px 18px;min-height:270px}
  .rate{gap:8px}
  .in{width:100%}
}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}a.cover{transition:none}.spin{animation-duration:3s}}

body.exam header.top{display:none}

[hidden]{display:none!important}